1. Field of the Invention
The present invention generally relates to a multiple processor system. More specifically, the present invention provides techniques for effective and efficient communication between multiple processor clusters.
2. Description of Related Art
Performance limitations have led to the development of a point-to-point architecture for connecting processors in a system with a single memory space. In one example, individual processors can be directly connected to each other through a plurality of point-to-point links to form a cluster of processors. Separate clusters of processors can also be connected. The point-to-point links significantly increase the bandwidth for coprocessing and multiprocessing functions.
In such a multiple processor, multiple cluster system, processors send probe requests in order to perform operations on particular memory lines that may be cached in local or remote nodes. Some common operations include read block and read block modify operations on memory lines. In many examples, packets associated with transactions such as read requests are transmitted between clusters of processors. However, mechanisms for transmitting packets such as read requests between clusters are limited.
Consequently, it is desirable to provide techniques for improving the mechanisms and techniques for communications between clusters in systems having multiple clusters of multiple processors connected using point-to-point links.